The present invention relates to radio frequency amplifiers. More specifically, the invention relates to RF amplifiers with variable gain.
GSM for cellular phones typically control power output by applying a control voltage (0-2 V) to control an amplifier's bias circuit. But power output is a nonlinear function of control voltage. At low power, the output power is very sensitive to small changes in the control voltage. Therefore, there remains a need for a system and method for linearizing the power output as a function of control voltage.